#include<iostream>
using namespace std;

int a[10000]={0};


int main(){
    int n=0;
    cin>>n;
    for(int i=0;i<n;i++)
        cin>>a[i];
    int k=0;
    cin>>k;
    int low=0;
    int high=n-1;
    int mid=0;
    while(low<=high){
        int mid=(low+high)/2;
        if(a[mid]>k){
            high=mid-1;
        }else if(a[mid]<k){
            low=mid+1;
        }
        if(a[mid]==k){
            cout<<"The element position is "<<mid<<".";
            return 0;
        }

    }
    cout<<"The element is not exist.";
    return 0;
}
